It is known that resonant electromagnetic sensors can be used to measure different physical values: pressure, acceleration or angular velocity. Such sensors have a vibrating structure: it is based on exploitation of a particular vibration mode of the vibrating structure, called the “useful mode”, that a value is determined which is linked to the physical variable which is to be accurately measured. For example, a variation in the vibration frequency of the vibrating beam of a pressure sensor permits determination of the pressure acting on the beam.
It is often necessary to rely on the high mechanical Q of the useful modes. Such Q values are generally obtained by means of optimization between three main factors:                a choice of the material of the vibrating structure, which most frequently results in the selection of crystalline material;        a mechanical structure design which must be adapted to the useful mode selected, and        creation of a relatively high vacuum around the vibrating structure.        
In parallel, the presence of parasitic modes may result in impairment of sensor performance because such presence also acts on the useful mode. This impairment is often all the more significant when the parasitic mode has a high Q.
Of the solutions taken from the prior art for damping these parasitic modes, mention may be made, for example, of: piezoelectric active or passive damping, gas damping, damping by means of a mechanical coupling with other more damped modes and lastly damping by addition of materials with significant mechanical losses, e.g. adhesives.
These various solutions are not perfect and each has certain disadvantages. In particular, piezoelectric damping requires the deposition of piezoelectric material on substrates as well as the deposition of electrodes: these deposits represent the addition of materials whose properties impair the sensor performance. Moreover, gas damping requires the encapsulation of the vibrating structures in a specified atmosphere and assurance of the stability of this atmosphere over time. Apart form the necessity to confine the gases in certain areas close to the structures, which results in high costs for its implementation and for ensuring it is kept in working order, this solution also has the disadvantage that it damps all vibration modes: the useful modes just as much as the parasitic modes.
It is generally accepted that prior art solutions for the damping of parasitic vibrations induce the following disadvantages: an addition of material impairing sensor performance, an absence of selectivity in the vibration modes which are damped, an increase in complexity of the mechanical structure of the sensors and lastly a significant increase in the fabrication costs of the latter.